Kidney Stones

Information, Diet Suggestions, and Resources

What are Kidney Stones?

Kidney stones occur when components in the urine that do not dissolve condense together and form stones that may cause blockages in the urinary system. The stress of this blockage within the tight areas of the urinary system including the ureters and the urethra causes great abdominal discomfort and pain. These stones may be caused by a low fluid intake, increased sweetened beverage intake, high calcium excretion in the urine, high oxalate in the diet or poor absorption of oxalate due to bowel disease, high animal protein in the diet, high sucrose in the diet, and high sodium in the diet.

The Diet

For all types of kidney stones, make sure that you are drinking adequate fluid-at least two liters of fluid daily and more during the warmer late spring, summer, and early autumn months- to form enough urine to prevent kidney stones from forming. Water is the best fluid for this purpose. It is also important to limit your sodium intake. Focus on getting a right balance of calcium for your age and sex, which varies from 1,000 to 1,200 and should come from diet. Calcium supplements should be taken only if needed but your doctor should tell you whether to take or limit calcium supplements.

In order to know the best diet to prevent the formation of kidney stones, it is important to know what type of kidney stone you produce. Speak with your doctor to identify the type of stone you are producing. Two of the four possible types of kidney stones have diets that are recommended to prevent the formation of stones.

For individuals with calcium stones, a diet that is low in animal protein and low  in oxalates and phosphate is recommended. Examples of foods high in oxalates  (which should therefore be avoided) include spinach, rhubarb, chocolate, black tea, and nuts. Individuals who produce a lot of calcium in the urine should follow a lower sodium diet. If an individual produces calcium oxalate stones, supplemental vitamin C must be avoided-it breaks down to oxalic acid and then to oxalate, thus significantly increasing the likelihood of calcium oxalate stone formation. In addition, too little calcium in the diet can cause increased oxalate absorption leading to kidney stones and too much calcium can lead to excess calcium excretion which will also contribute to stone formation. Again, consult with a dietitian that can assist you with the right plan that meets your medical evaluation.

For individuals with uric acid stones, where the urine is excessively acidic, a diet low in purines, which are found in animal protein such as meats, fish, and shellfish, is recommended. In addition, the consumption of alcoholic beverages should be limited.


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